We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
Click here to Donate Now (View Announcement)
Sister, we're talking about M/J 2011 v3...at least i am..v.53 is about moles ratio ....very easy ...........calculate mass of lead (C-A) ....then mass of oxygen(C-B) ....the other columns ...get the no. of moles by diving each mass by Ar of the element ....plot a graph of moles of lead against moles of oxygen ,...the slope give u a ratio hence the formula of the compound
ah sorry i just saw your tag,ill post my doubt herepearl angel we're discussing ur question here
opps sorry
Calm down and chillopps sorry
well i am not very sure about solubility myself !
the MS is not clear as well it say "
Correct units,(allow g/100g without the solidus)"
i dnt understand what exactly solidus mean here?!
ah sorry i just saw your tag,ill post my doubt here
im confused about the solubility part but other than that,we find the solid by subtracting ' (D) mass of boiling tube,water and solid' from ' (C) mass of boiling tube and water' OR we find solid by subtracting ' (E) mass of water' from ' (D) mass of boiling tube,water and solid' ?? please help me out i will be very grateful
Riight! Thankyou
But for qs no. 1 in ms says that (allow no mark for, if the mixture is mixed at temperature and then stopwatch started."but the ms says that yu can't start timing w/0 allowing the reactants to reach the required temperature"
Time must be only measured for the temperature on which we are required to carry an experiment (we are investigating temp effect) so we only care for the temp we are investigating..
u can warm them separately but their is a possible for heat losses when u mixing them etc (reactant temp changes)
nhe bahi, it is saying:
But qs no. 1 says that no mark if the mixture is mixed and then stopwatch is started
However, in (d) in order
to access the ‘temperature’ mark using such a water-bath
‘equilibration’ must be stated or clearly implied.)
means if nothing stated in diagram for temp as mention
check for something (same/equal) in d part!
did ur anamolies get straight path on line
for Q2d
a little fact:
high temperature @ 80 graph shows solubility
lower temp @ 35 shows solid deposits
Q's says find mass deposit for 50g by using graph
brilliant attempt by MaxStudentALevel
I got 14.3g deposited.
----> According to my curve at 85degrees=40g per 100g so 20g per50g (SO 20g dissolved)
-----> Also same for 35 degrees = 11.5g per 100g so 5.7 per 50 (SO 5.7g dissolved)
MEANING initial mass dissolved -final mass dissolved = deposited solid.
----> 20-5.7 = 14.3g
Dua karna for me!
how do u put it straight in the conical flask? like u just throw it in there ? this will start the reaction immediately and u still didn't connect ur apparatus to a gas syringe so loss of oxygen (thats an error) and u wont be able to determine the rate if u do it that way. so what the mark scheme is saying is that u separate the peroxide from the catalyst by using a divided flask for example and as soon as u remove the barrier between them u can start ur stop watch and watch ur gas syringe being filled with oxygen!
For almost 10 years, the site XtremePapers has been trying very hard to serve its users.
However, we are now struggling to cover its operational costs due to unforeseen circumstances. If we helped you in any way, kindly contribute and be the part of this effort. No act of kindness, no matter how small, is ever wasted.
Click here to Donate Now